History - Populus Sion

Nov 05, 2018 (SirPL)

Added reference to Graduale Romanum 1974

sources
[{"chant_id":"356","source":"2","page":"4","sequence":"1","extent":"1"},{"chant_id":"356","source":"3","page":"327","sequence":"2","extent":"2"},{"chant_id":"356","source":"4","page":"18","sequence":"1","extent":"1"}]